Connecting ideas and people

April 2013 Revisit: Super Coelacanths from Outer Space… or Something

Way back in February WDTM? touched on the idea of bacterial antibiotic resistance, what it means to people, and why it’s spreading. As it turns out, it means something to sea life too, as the resistant strains produced by our irresponsible behavior are finding their way into the oceans and sickening the animals there, as reported in the May issue of Scientific American. The ugly cycle can complete if we eat seafood tainted with the superbugs or when oceangoing people develop hard to treat infections if wounded. Circle of life, I guess.

In a meeting this month of the American Physical Society, Shawn Bishop, of the Technical University of Munich, Germany, described preliminary research of new forensic techniques to confirm past offenses of supernovae trying to gun us down. He was able to identify iron-60, an isotope with a half life too short for any from the birth of our solar system to still be present on Earth, in fossilized ocean-dwelling bacteria that use iron-rich magnetite to navigate. Bishop found high concentrations in the bacteria from about 2.2 million years ago, leading other researchers to suggest a known supernova from this time period in the Scorpius-Centaurus stellar association as the culprit. Busted. Fortunately, at over 400 light years away, the perp wasn’t near enough to give as both barrels or, as Shawn himself put it, “That we’re here talking about it means it wasn’t too close.”

If you and I aren’t the pinnacles of evolution, then what about the “living fossils” that haven’t changed for ages? They must be doing something right. Check that, they are still changing. A fish called the coelacanth is perhaps the most famous example, as it was only rediscovered in the waters off South Africa in 1938, after being thought long-extinct. As seen in April’s issue of Nature, the prehistoric beast’s genome has now been fully sequenced and it reveals that while many of its genes have been slow to change, perhaps due to a lack of selective pressure deep in the ocean where it lives, a large number of non-coding parts seem to be moving around. Although the role of these bits in shaping physiology is not really clear, we now see that even after 4 billion years of evolutionary success, the famous fish still isn’t finished.

Unfortunately, in the near term, we may have to be ready to adapt to climate change before it can be completely counteracted. We’ll have to develop engineering solutions to deal with floods and superstorms, and agricultural innovations to continue food production. Don’t expect our “successful evolution” to come to the rescue; people are not birds or sea urchins. The cost of such measures is sure to be enormous. As we deal with the new world we’ve precipitated, perhaps the best lesson is that future consequences need to be considered for all our actions. We don’t need another global shift while we’re cleaning up the mess we already have.